Estimate how much waterproofing coating or membrane you need for a roof, bathroom or basement — by area, product type and number of coats.
Coverage rates vary by brand and surface porosity — these are representative mid-range figures for planning. Check your specific product's datasheet before final ordering, and always add 10% for surface absorption and wastage.
Cementitious coatings are trowel- or brush-applied slurries measured by weight (kg); bituminous and PU coatings are liquid-applied and measured by volume (liters). Their coverage rates aren't directly comparable — always check per-coat coverage on your specific product's datasheet, since formulations vary between manufacturers.
A single coat almost never achieves full, pinhole-free coverage — industry practice for waterproofing membranes is a minimum of two coats, often applied in perpendicular directions, to ensure a continuous, defect-free barrier.
Porous, dusty or uncured concrete absorbs significantly more material than the datasheet figure and can compromise adhesion entirely. Proper surface cleaning and priming — not just a thicker coat — is what actually prevents most waterproofing failures.